<!DOCTYPE html>
<html>
    <head>
        <meta charset="utf-8">
        <title></title>
        <style>
            .class1 {
                width: 200px;
                height: 100px;
                background: palegreen;
                float: left;
            }    

            .class2 {
                width: 250px;
                height: 130px;
                background: gold;

                float: left;
            }

            .class3 {
                width: 300px;
                height: 180px;
                background: red;
                float: left;

            }
			
			
			.clear{
				clear:both;
			}
			
			
        </style>
    </head>
    <body>

		<div id="" style="border:solid 1px #000000;" >
			<div class="class1">我是块级元素1，没有设置浮动</div>
			
			<div class="class2">我是块级元素2，没有设置浮动222222222222222222222222222222222222222</div>
			
			<!-- <div class="class3">我是块级元素3，没有设置浮动</div> -->
			
		</div>
		<div class="clear"></div>
		<p>
			段落
		</p>
      


    </body>
</html>